The invention relates to a storage device and a navigation system.
With navigation systems, it is possible to calculate routes between a starting point and a destination point based on an electronic road map according to various criteria. For this purpose, it is proposed to assign cost values (for example travel time, travel distance, energy consumption, etc. or any combinations based thereon) to individual, digitized road sections (so-called “links”) and to determine a route with low or minimal overall costs.
So-called Points of Interest (POIs) often form part of the electronic road map or other storage devices which can be connected to communicate with the navigation system. These location information objects usually include the name of a defined location, if appropriate a brief description of the location, and the geographical coordinates of the location.
It is known to display POIs which lie in the vicinity of the current location or in the vicinity of the current route during the journey by means of a navigation system.
In doing so, it is an objective to specify, in particular display, the distance from the current location (current vehicle position or current position of the navigation system) to the POIs in each case together with the POIs. Here, the distance calculation is either based on the linear distance between current location and POI or on the road route to the POI. The first alternative is very inaccurate and the second alternative is very calculation-intensive, as current routes from the current location to all POIs to be displayed must be calculated for this purpose.
The invention is now based on the object of specifying an improved technical teaching compared with the prior art.
This and other objects are achieved by a navigation system, and associated storage device, according to the invention. The storage device is configured such that a multiplicity of location information objects, which in each case represent a location, is stored, and a distance information object, which in each case represents the distance by road from the location of a location information object to the freeway exit closest to the location, is stored in association with the location information objects in each case. The navigation system includes the storage device and has an interface for accessing the storage device, and a computer device configured such that the calculation of a total distance to a location represented by a location information object is based on the formation of a total of a first distance and a second distance. The first distance is determined by the distance by road from the current location to the freeway exit which is closest to the location represented by the location information object, and the second distance is determined by the distance information object which is stored in association with the location information object.
The invention is accordingly based on storing the distance (for example, based on linear distance, fastest road route or shortest road route) between the POI and the freeway exit which is closest to the POI (for example with regard to linear distance, fastest road route or shortest road route), together with the location information objects (POIs) in each case.
A storage device according to the invention, such as for example a hard disk or a DVD, is configured in such a way that a multiplicity of location information objects, which in each case represent a location, is stored thereon, and that a distance information object, which in each case represents the distance by road (distance to be covered, in particular, on the shortest, fastest or most efficient route) from the location of a location information object to the freeway exit closest to the location (with regard to road distance or linear distance), is stored thereon in association with the location information objects in each case. Here, the location of the freeway exit can be determined, for example, by coordinates or other parameters of a position in the vicinity of the appropriate freeway exit.
By this means, in order to calculate a total distance from a current position to a location of a location information object, it is only necessary to comparatively laboriously calculate the distance by road from the current position to the freeway exit closest to the location; the total distance is then simply given by the sum of this calculated distance by road and the distance by road associated with, in particular stored in association with, the location information object.
This enables the total distance from a current position to a location of a location information object to be determined accurately and easily, and therefore quickly and with little computer power. This is particularly advantageous when the total distances to a multiplicity of locations of different location information objects are to be determined.
Along with the distance information object, which in each case represents the distance by road from the location of a location information object to the freeway exit closest to the location, further distance information objects can be stored associated with the location information object, which in each case preferably represent the distances by road from the location of the location information object to a further freeway exit closest to the location of the location information object.
Preferably, the multiplicity of location information objects is in each case stored associated with at least one freeway exit identification (ID, name or coordinates of the freeway exit), by means of which the freeway exit which lies closest to the location of the location information object (for example, with regard to distance by road or linear distance) is determined.
Preferably, the storage device is designed as an electronic road map or includes an electronic road map, wherein geographical coordinates are in each case associated with the location information objects. This also enables routing directions to be given to the location of a location information object.
A preferred refinement provides that the location information objects in each case represent a Point of Interest (POI, location of particular interest, tourist attraction).
A navigation system according to the invention, which, for example, is designed as part of a motor vehicle or a cell phone, includes the aforementioned storage device and an interface for accessing the storage device.
A computer device, such as, for example, a program-controlled processor device, is designed or configured in such a way that the calculation of a total distance to a location represented by a location information object is based on the formation of a total of a first distance and a second distance.
The first distance is determined by the distance by road from the current location (of the navigation system) to the freeway exit which is closest to the location represented by the location information object.
The second distance is determined by the distance information object which is associated with, in particular stored in association with, the location information object.
By this means, in order to determine a total distance from a current location to a location of a location information object, it is only necessary to comparatively laboriously calculate the distance by road (first distance) from the current location to the freeway exit closest to the location, but in a manner which is known per se. However, the total distance is then simply given by the sum of this calculated distance by road and the distance by road (second distance) stored in association with the location information object.
A refinement of the invention is that the first distance is derived from the route to a driving destination which is currently determined by the navigation system and, if appropriate, is currently being followed, and which is not part of the location information object. The first distance is preferably based on a sub-route of the currently determined route. This enables the first distance to be determined with little effort.
Of course, it is also within the scope of the invention, that, as well as the distances between the locations of location information objects and freeway exits, distances between the locations of location information objects and other prominent locations, such as crossroads for example, are in each case also associated with the location information objects, and these distances are also used for calculating the total distance. It is likewise a matter of course that, as well as the stated location information objects, location information objects with which no distance information object is associated can also be provided.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawing.